The genus Chryseobacterium was first proposed in 1994 and consisted of six
species, it has since rapidly expanded and currently consists of 36 different species. Most
of these species have been proposed within the last 3 years. Bacteria belonging to the
genus Chryseobacterium are aerobic, non-sporulating, non-motile, Gram-negative rods
which produce a yellow pigment. Chryseobacterium species have been found in a variety
of environmental, industrial and clinical surroundings. Several species have already
exhibited pathogenic characteristics for different animals and for humans as well.
The first aim of this study was to evaluate the potential pathogenesis of 14
Chryseobacterium species by evaluating a variety of known virulence factors (enzymes),
to evaluate their antimicrobial resistance patterns as well as to determine their resistance
to four commercially available disinfectants. When the production of specific enzymes
by the 14 Chryseobacterium species were evaluated, it was found that C. daecheongense,
C. joostei, C. shigense, C. soldanellicola, C. taeanense, C. vrystaatense together with
C. indologenes which was regarded the standard organism, can be regarded potentially
pathogenic. The species most resistant to all of the antimicrobials evaluated, were
C. indologenes, C. indoltheticum and C. joostei. The most susceptible to the
antimicrobials was C. balustinum. It was also found that it would be best to treat an
infection of Chryseobacterium with antimicrobials of the quinolone class or cephem
class. The penicillin class would seem to be the least effective. The disinfectant
resistance was determined by determining the MIC for each tested disinfectant, with a
higher MIC exhibiting more resistance. The species with the highest resistance were
C. gleum, C. indologenes and C. joostei. The disinfectants tested were for use either on
hard surfaces or on wounds (personal use). From the results obtained disinfectants for
use on hard surfaces are more effective than those meant for personal use. In conclusion
it can be said that C. gleum, C. indologenes and C. joostei may be regarded as the most pathogenic of the 14 Chryseobacterium species evaluated. Chryseobacterium joostei
may be less of a threat as it was first isolated from raw milk, which had not yet
undergone pasteurization and as such, is less likely to come into contact with the general
population. It would seem that C. gleum and C. indologenes however come into contact
with people more often as they have been found in or on ill or wounded individuals on
several different occasions.
The second aim of the study was to evaluate possible degradation of aflatoxin B1
by the 14 Chryseobacterium species. After statistical analysis, it was concluded that no
Chryseobacterium species was able to degrade aflatoxin. This study, however contributed
to the knowledge on the significance of these bacteria.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-09182009-130955 |
| Date | 18 September 2009 |
| Creators | van Wyk, Esias Renier |
| Contributors | Prof PJ Jooste, Dr CJ Hugo |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-09182009-130955/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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